Toyota Avalon Drive Modes - Affect on EPA MPG Estimates

The Toyota Avalon like many Toyota cars come with drive modes like Eco, Normal and Sport. These different driving modes affect performance and thus MPG. How accurate are the EPA estimates then in cars with different modes? Depends.

What do these buttons do for your MPG? Quite a bit it turns out.

Toyota says the Avalon gets 21/31/25 (mpg city/highway/combined), yet it comes with three different drive modes that can affect MPG. The three different modes are really just two different options beyond normal (Eco and Sport). What makes them different?

Driving a Toyota Avalon like this in Sport mode sure is fun, yet not very economical. Image Courtesy of Motor Trend.

These modes do have an affect on MPG with many studies suggesting a difference in the realm of around a 10 percent improvement/decrease.

EPA Estimates

What then does the EPA have to say about the different modes? According to a Cars.com story, most of the cars that have them get their recommended mileage from normal mode, although it depends on the way drivers use the vehicle.

The EPA has a 2009 statement on how it handles these systems on a case by case basis.

If a car has various modes but defaults back to Normal whenever you turn the engine back on, the EPA draws its ratings from the Normal mode.

But vehicles that default to a fuel-saving mode at start-up — like the 2014 Jeep Grand Cherokee — set economy as the “predominant” mode from which the EPA bases its ratings, the agency told Cars.com.

If a car has multimode system that stays in whatever you last drove, the EPA may not be able to establish a “predominant” mode. In such cases, “the vehicle is tested in the various modes and the fuel economy results from the best and worst modes are harmonically averaged,” EPA officials wrote. “For example, if a vehicle has a sport mode, normal mode, and economy mode, the fuel economy results of the sport and economy modes would be averaged.”

Automakers can (and often do) submit customer surveys or technical data that show that customers use one particular mode most of the time — so if Honda determined that 80% of Civic owners drove everywhere in Econ mode, then it could request that the EPA rerate the Civic using economy-mode driving. If it’s too early to assess the mode that drivers use most often — say, with a fresh redesign or introduction — then automakers can exercise “good engineering judgment” to determine what’s predominant, the EPA said.

What does this mean for the average driver? You could get better gas MPG than the EPA estimates if you only drive in ECO mode.

Next time you are concerned about wasting gas, push the button and switch on ECO, your wallet will thank you.